package com.example.myapplication;
//C:\Users\liuzc\Desktop\MyApplication\app\src\main\java\com\example\myapplication\MyDatabaseHelper.java(class)
import android.content.Context;  //这里要额外import
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase;
import android.widget.Toast;

public class MyDatabaseHelper extends SQLiteOpenHelper {
    public static final String CREATE_BOOK="Create table Book("
            +"id integer primary key autoincrement,"
            +"name text)";
    public static final String CREATE_CATEGORY="create table Category("
            +"id integer primary key autoincrement,"
            +"category_name text,"
            +"category_code integer";
    private Context mContext;
    public MyDatabaseHelper(Context context,String name,SQLiteDatabase.CursorFactory factory,
                            int version){
        super(context,name,factory,version);
        mContext=context;
    }
    @Override
    public void onCreate(SQLiteDatabase db){
        db.execSQL(CREATE_BOOK);
        Toast.makeText(mContext,"Create succeded",Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion){

        db.execSQL("drop table if exists Book");
        db.execSQL("drop table if exists Category");
        onCreate(db);
    }

}
